package examples_referal;



import org.codehaus.commons.compiler.CompilerFactoryFactory;
import org.codehaus.commons.compiler.IExpressionEvaluator;


/**
 * A test program that allows you to play around with the
 * {@link org.codehaus.janino.ExpressionEvaluator ExpressionEvaluator} class.
 */
public final class ExpressionDemo extends DemoBase {
    public static void main(String[] args) throws Exception {
        Class    optionalExpressionType = null;
        String[] parameterNames         = {};
        Class[]  parameterTypes         = {};
        Class[]  thrownExceptions       = {};
        String[] optionalDefaultImports = null;

        int i;
        for (i = 0; i < args.length; ++i) {
            String arg = args[i];
            if (!arg.startsWith("-")) break;
            if (arg.equals("-et")) {
                optionalExpressionType = DemoBase.stringToType(args[++i]);
            } else
            if (arg.equals("-pn")) {
                parameterNames = DemoBase.explode(args[++i]);
            } else
            if (arg.equals("-pt")) {
                parameterTypes = DemoBase.stringToTypes(args[++i]);
            } else
            if (arg.equals("-te")) {
                thrownExceptions = DemoBase.stringToTypes(args[++i]);
            } else
            if (arg.equals("-di")) {
                optionalDefaultImports = DemoBase.explode(args[++i]);
            } else
            if (arg.equals("-help")) {
                System.err.println("Usage:");
                System.err.println("  ExpressionDemo { <option> } <expression> { <parameter-value> }");
                System.err.println("Compiles and evaluates the given expression and prints its value.");
                System.err.println("Valid options are");
                System.err.println(" -et <expression-type>                        (default: any)");
                System.err.println(" -pn <comma-separated-parameter-names>        (default: none)");
                System.err.println(" -pt <comma-separated-parameter-types>        (default: none)");
                System.err.println(" -te <comma-separated-thrown-exception-types> (default: none)");
                System.err.println(" -di <comma-separated-default-imports>        (default: none)");
                System.err.println(" -help");
                System.err.println("The number of parameter names, types and values must be identical.");
                System.exit(0);
            } else
            {
                System.err.println("Invalid command line option \"" + arg + "\"; try \"-help\".");
                System.exit(1);
            }
        }

        if (i >= args.length) {
            System.err.println("Expression missing; try \"-help\".");
            System.exit(1);
        }
        String expression = args[i++];

        if (parameterTypes.length != parameterNames.length) {
            System.err.println(
                "Parameter type count ("
                + parameterTypes.length
                + ") and parameter name count ("
                + parameterNames.length
                + ") do not match; try \"-help\"."
            );
            System.exit(1);
        }

        // One command line argument for each parameter.
        if (args.length - i != parameterNames.length) {
            System.err.println(
                "Parameter value count ("
                + (args.length - i)
                + ") and parameter name count ("
                + parameterNames.length
                + ") do not match; try \"-help\"."
            );
            System.exit(1);
        }

        // Convert command line arguments to call arguments.
        Object[] arguments = new Object[parameterNames.length];
        for (int j = 0; j < parameterNames.length; ++j) {
            arguments[j] = DemoBase.createObject(parameterTypes[j], args[i + j]);
        }

        // Create "ExpressionEvaluator" object.
        IExpressionEvaluator ee = CompilerFactoryFactory.getDefaultCompilerFactory().newExpressionEvaluator();
        ee.setExpressionType(optionalExpressionType);
        ee.setDefaultImports(optionalDefaultImports);
        ee.setParameters(parameterNames, parameterTypes);
        ee.setThrownExceptions(thrownExceptions);
        ee.cook(expression);

        // Evaluate expression with actual parameter values.
        Object res = ee.evaluate(arguments);

        // Print expression result.
        System.out.println("Result = " + DemoBase.toString(res));
    }

    private ExpressionDemo() {}
}
